(RNN) - The estimated number of children in the U.S. with autism increased nearly one-third in two years, according to figures released by the Centers for Disease Control and Prevention.

One in 88 children had autism spectrum disorder (ASD) in 2008, according to the CDC. That number grew to 1 in 68 in 2010, an increase of 30 percent, in the most recent report provided Thursday.

The CDC began tracking the disorder in 2000 using the Autism and Developmental Disabilities Monitoring (ADDM) Network. The most recent study involved all health and education records for 8-year-olds in 11 states: Alabama, Wisconsin, Colorado, Missouri, Georgia, Arkansas, Arizona, Maryland, North Carolina, Utah and New Jersey.

The study found boys are almost five times more likely to have autism than girls, and it is more common in white children than those of minority races.

Autism is a group of developmental disabilities that can cause significant social, communication and behavioral challenges.

Symptoms can range from mild to severe and vary in each person, but people with the disorder commonly have problems with social interaction.